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Forum Index : Microcontroller and PC projects : Silicon Chip March 2024 editorial....
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Grogster Admin Group  Joined: 31/12/2012 Location: New ZealandPosts: 9066 |
The editorial in the March 2024 issue of Silicon Chip, makes some excellent and very valid points about using flash-drives or SSD's as a long-term storage medium. I have old PATA hard-drives that are about 30 years old, and they still read just fine!   Nothing on those old drives is important, but the fact remains that magnetic platter-based HDD's still seem the best choice for off-line archival backups - for a few decades at least. Thoughts? Opinions? The editorial in SC talks about how the charge on the SSD's can dissipate over time, which is totally correct, and even talks about SSD's sitting in machines running 24/7/365 - but if the data in certain cells is never "Refreshed"(copied and rewritten again), that these drives can also fail or cause problems. The article goes on to mention that there are softwares that can automate this refreshing process for you, so do any of the members have anything they can recommend? I would prefer a Linux-type USB you can boot, and it will set about refreshing the entire SSD. That could be an issue with Windoze-based SSD's, as I understand that reading NTFS is no problem in Linux, but WRITING to NTFS volumes is still a bit of an issue, due to the closed-source nature of NTFS. Smoke makes things work. When the smoke gets out, it stops! |
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| JohnS Guru  Joined: 18/11/2011 Location: United KingdomPosts: 3661 |
Is it enough to simply read the SSD block by block? (dd is good enough if so) If not, maybe per group of blocks: read, invert, write it back, then restore the original. (Will take forever! Use a big group so as to speed it up.) John |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 3552 |
Look at this video tube computer with magnetic drum memory A 1959 computer is started up, and the magnetic drum still has clock and sync pulses on it. At 19:56 the clock pulses are measured. By the way, I think it is impressive how these machines worked. In this series many of the detailed circuits are described. Volhout PicomiteVGA PETSCII ROBOTS |
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Martin H. Guru Joined: 04/06/2022 Location: GermanyPosts: 903 |
looks like the template for the computers on the Enterprise, Pre Time-Tunnel 'no comment |
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palcal Guru Joined: 12/10/2011 Location: AustraliaPosts: 1804 |
I found this from a Kingston representative.... "It is better to be ignorant and ask a stupid question than to be plain Stupid and not ask at all" |
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PilotPirx Regular Member  Joined: 03/11/2020 Location: GermanyPosts: 66 |
Normally the data retention on SSD Drives with MLC or 3D-TLC Flash (multi level cell with 2-Bit per cell or triple level cell with 3-Bit)is around 10 Years without power supply, but only if the used Write/Erase cycles are below 10%. If they are powered and in use, the internal wear leveling swaps the data to other blocks if the voltage-level of the storage cell is going bad. So you need a lot of spare cells. Therefore its important to have a lot of unused flash on your SSD for a long lifetime. All of the above is only for ambient temperatures in the normal range. High temperatures also stress SSDs enormously and shorten the service life of the data. But - a lot of the new SSD with high density for the consumer market are QLC Flash (quad level cell with 4-bit per cell and 300 write/erase cycles) which have a data retention of only 1-2 years without power. For industry use you have other flash which has more Write/Erase cycles with SLC and pSLC (pseudo single level cell). This flash is more expensive than the consumer flash. I use HDDs for longtime backups. My company sells SSDs for the industry, so I'm familiar with the subject matter |
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| JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 3661 |
That's news - but do HDD makers actually say that (so far haven't found it to be so)? I expect many people buy a computer with OS etc preinstalled and vast amounts of the disk never get rewritten - unless Windows etc do this in the background? I never heard of it if so. John |
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PeteCotton Guru Joined: 13/08/2020 Location: CanadaPosts: 316 |
Back in the early 90's, each year the System Administrator of the company I worked for, liked to copy all of the files off the VAX server drives and into a backup, and then restore the files to a new drive and swap it in/out. His argument was that not only did it prove the backups worked, but also he felt that re-writing the magnetic imprint on the drive would stop it degrading. I'm not sure if he was right or not, but it made laymans sense to me. Pete |
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| Amnesie Guru Joined: 30/06/2020 Location: GermanyPosts: 382 |
Yeah this applies to SDcards too... We need MMBasic to support Floppy or HDD! :D -Daniel |
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| EDNEDN Regular Member Joined: 18/02/2023 Location: United StatesPosts: 64 |
SATA is a very easy command set to do. If there was an Pico to SATA connector easily available it would be very straight forward to do. |
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Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 5735 |
First you need an OS. The Pico hasn't got one, it just looks like one. Support for file handling isn't really an OS as such. Use a SD card to copy everything to the HDD on your PC - and into cloud storage if you must. You'll use far less pins. Spinning rust drives are still very good. :) Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 3552 |
SD card versus HDD ? Why do you think the bits in the picomite flash memory would be more robust than the bits on an SD card ? I guess the pico would die before the SD card does. Absolutely nonsense to revert to SATA for PicoMite. If you want something that will withstand the time, use core rope memory, like the Apollo missions had in their guidance computer. Or carve the information in stone, like the Egyptians did (actually quite similar). Volhout PicomiteVGA PETSCII ROBOTS |
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| Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 5735 |
Or you can resort to writing to a HDD via a serial interface that you might need to design first. :) I suggested transfer via SD card (sneakernet) because it's more straightforward than using XMODEM if you have a load of files to back up. Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| EDNEDN Regular Member Joined: 18/02/2023 Location: United StatesPosts: 64 |
No.... I was kind of thinking it could be an alternative lower layer to the FAT file system support that is already in MMBasic. Rather than reading and writing blocks on an SD-Card, it could (based on the drive letter) know to use the SATA support instead. Everything would be there. The drive formatting. The hierarchical directory support. Etc. The FAT file code would just be writing to a SATA interface instead of the SD-card. Edited 2024-04-25 02:06 by EDNEDN |
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| JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 3661 |
Done that way you'd have a HDD max size the same as the SD card max size supported. Some work on the actual hardware needed of course :) Or send/receive HDD blocks over an existing interface to a host which does the actual I/O. (I did this rather a long time ago in the days of the 8086 over RS232. Think of it as remote I/O.) John |
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| Amnesie Guru Joined: 30/06/2020 Location: GermanyPosts: 382 |
Hello because it is a matter of fact, that flash memory isn't made for long term storage. It is just for this purpose of robustnes. I encountered A LOT of faulty and corrupt data on SD cards over time. I am not speaking of removing the SD as a main storage. And using another computer to backup is no option. The whole point of a "Boot-To-BASIC" computer is to be resilient  And for REAL backups I use something called MDSICs which are pretty much like you've written (carved / etched by laser into a special material). For small and crucial data I am even using "matrices" printed on paper (acid free) as backup which can be read in via a scanner. It has reed solomon error correction too and can even corrected manually. This piece of software is called Paperback (https://gigazine.net/gsc_news/en/20120817-paperback/) Greetings Daniel Edited 2024-04-25 04:19 by Amnesie |
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| EDNEDN Regular Member Joined: 18/02/2023 Location: United StatesPosts: 64 |
Yes. The manual says: "Maximum SD card size is 2GB formatted with FAT16 or 2TB formatted with FAT32." 2TB should be enough. Yeah... That is the real problem. I don't think there are any simple and small shields or hats for the Pico that do SATA. Part of the problem might be the signals are differential and getting the voltage levels to do that on a small shield. |
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| Amnesie Guru Joined: 30/06/2020 Location: GermanyPosts: 382 |
There is a HDD shield for Arduino but sadly only on german and I can't find any schematic. https://www.youtube.com/watch?v=HpQQx_lyQKM&t=7s https://luca-elektronik.de/index.php?main_page=product_info&cPath=7&products_id=160 Greetings Daniel |
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| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9066 |
Some interesting posts on this thread! It would therefore seem, that for archival purposes, good old magnetic HDD's are still the way to go - for up to, say, twenty years or so. As has been mentioned, no archival medium is perfect. There are some very good media like M-disc that has been mentioned, but the kink in the idea, is having a drive that can actually read the disc later on down the track. Without a way to read the data on those discs, they are basically nothing more then beer coasters.  Even SATA is now a technology largly being replaced by NVMe and M.2 interfaces. Yes, I know you can also have SATA over the M.2 interface, but the point being, that given time, even the SATA connectors will start to vanish in favour of multipule plug-in M.2 SSD's. I guess there will always be some form of adaptors. You can get SATA-to-IDE adaptors allowing you to connect old IDE HDD's to a SATA port, so you'll probably get M.2-to-SATA adaptors - assuming they don't ALREADY exist - I have not looked.  However, it would seem that good-old spinning HDD's are still the best choice for offline/not-powered archive storage. For a few decades anyway. Smoke makes things work. When the smoke gets out, it stops! |
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phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 1790 |
Even carving in stone isn't always enough. If not for the chance discovery of the Rosetta Stone Egypt's monuments may as well have blank walls. |
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